from __future__ import print_function, absolute_import
import torch
import pdb
__all__ = ['accuracy']

# def accuracy(output, target, topk=(1,)):
#     """Computes the precision@k for the specified values of k"""
#     maxk = max(topk)
#     batch_size = target.size(0)
#     _, pred = output.topk(maxk, 1, True, True)
#     pred = pred.t()
#     correct = pred.eq(target.view(1, -1).expand_as(pred))

#     res = []
#     for k in topk:
#         correct_k = correct[:k].view(-1).float().sum(0)
#         res.append(correct_k.mul_(100.0 / batch_size))
#     return res


def accuracy(output, target, topk=(1,)):
    """Computes the accuracy over the k top predictions for the specified values of k"""

    maxk = max(topk)
    batch_size = target.size(0)
    _, pred = output.topk(maxk, 1, True, True)
    pred = pred.t()
    correct = pred.eq(target.view(1, -1).expand_as(pred))


    res = []
    for k in topk:
        correct_k = correct[:k].view(-1).float().sum(0, keepdim=True)
        res.append(correct_k.mul_(100.0 / batch_size))
    return res


